<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>留言板</title>
    <style>
        .container {
            width: 350px;
            height: 300px;
            margin: 0 auto;
            /* border: 1px black solid; */
            text-align: center;
        }

        .grey {
            color: grey;
        }

        .container .row {
            width: 350px;
            height: 40px;

            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .container .row input {
            width: 260px;
            height: 30px;
        }

        #submit {
            width: 350px;
            height: 40px;
            background-color: orange;
            color: white;
            border: none;
            margin: 10px;
            border-radius: 5px;
            font-size: 20px;
        }
    </style>
</head>

<body>
    <div class="container">
        <h1>留言板</h1>
        <p class="grey">输入后点击提交, 会将信息显示下方空白处</p>
        <div class="row">
            <span>谁:</span> <input type="text" name="" id="from">
        </div>
        <div class="row">
            <span>对谁:</span> <input type="text" name="" id="to">
        </div>
        <div class="row">
            <span>说什么:</span> <input type="text" name="" id="say">
        </div>
        <input type="button" value="提交" id="submit" onclick="submit()">
        <!-- <div>A 对 B 说: hello</div> -->
    </div>

    <script src="js/jquery.min.js"></script>
    <script>
           // 页面在加载时,发送请求获取数据
           $.ajax({
               type:"get",
               url: "/message/get",
               success:function(body){
                  for(var message of body){      // 遍历一下响应集合
                      var html = "<div>" +message.from + " 对 " +message.to + " 说: "+ message.message+" </div>";
                       
                      // 将 节点添加到 页面上
                      // 用class选择,添加到上面的 container
                      $(".container").append(html);
                  }
               }
           });
        function submit(){
            //1. 获取留言的内容
            var from = $('#from').val();
            var to = $('#to').val();
            var say = $('#say').val();
            if (from== '' || to == '' || say == '') {
                return;
            }
           //  获取到信息了,发送请求将数据给 后端
           $.ajax({
             type: "post",
             url: "/message/put",
             data:{
                from: from,
                to: to,
                message:say
             },
             success:function(result){
                if(result==true){
                    // 添加成功了,才构造节点,清空输入框
                    //2. 构造节点
                    var divE = "<div>"+from +"对" + to + "说:" + say+"</div>";
                   //3. 把节点添加到页面上
                    $(".container").append(divE);
                    //4. 清空输入框的值
                    $('#from').val("");
                    $('#to').val("");
                    $( '#say').val("");
                }else{
                    // 不成功
                    alert("发布失败");
                }
             }

           });
        }
        
    </script>
</body>

</html>